package net.jxiny.oschina.util;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.PixelFormat;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;

import org.json.JSONArray;
import org.json.JSONObject;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.OutputStream;
import java.io.RandomAccessFile;
import java.io.Serializable;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.concurrent.atomic.AtomicLong;

/**
 * https://github.com/yangfuhai/ASimpleCache
 * 缓存文件放置在/data/data/app-package-name/cache/路径下，缓存的目录默认为ACache，缓存大小和数量均由ACache中的final变量控制。
 */
public class ACache {
    /**
     * 设置的缓存的时间
     */
    public static final int TIME_HOUR = 60 * 60;//1小时
    //1天
    public static final int TIME_DAY;

    static {
        TIME_DAY = 86400;
    }

    /**
     * 设置的缓存的大小
     */
    private static final int MAX_SIZE = 1000 * 1000 * 50; // 50 MB
    private static final int MAX_COUNT = Integer.MAX_VALUE; // 不限制存放数据的数量
    /**
     * 声明一个Map，用于存放ACache对象
     */
    private static Map <String, ACache> mInstanceMap = new HashMap <String, ACache> ( );
    /**
     * 缓存管理器
     */
    private ACacheManager mCacheManager;

    //ACache类的构造方法为private的，所以只能通过get方式获取实例。
    private ACache(File cacheDir, long max_size, int max_count) {
        //如果cacheDir文件不存在并且无法新建子目录，则报错
        if (!cacheDir.exists ( ) && !cacheDir.mkdirs ( )) {
            throw new RuntimeException ( "can't make dirs in " + cacheDir.getAbsolutePath ( ) );
        }
        //实例化缓存管理器对象
        mCacheManager = new ACacheManager ( cacheDir, max_size, max_count );
    }

    //默认情况下调用该方法
    public static ACache get(Context ctx) {
        return get ( ctx, "ACache" );
    }

    public static ACache get(Context ctx, long max_zise, int max_count) {
        File f = new File ( ctx.getCacheDir ( ), "ACache" );
        return get ( f, max_zise, max_count );
    }

    public static ACache get(Context ctx, String cacheName) {
        File f = new File ( ctx.getCacheDir ( ), cacheName );
        return get ( f, MAX_SIZE, MAX_COUNT );
    }

    public static ACache get(File cacheDir) {
        return get ( cacheDir, MAX_SIZE, MAX_COUNT );
    }

    //最终默认调用的实例方法
    public static ACache get(File cacheDir, long max_zise, int max_count) {
        //Map中的Key值为cacheDir.getAbsoluteFile() + myPid()，例如：/data/data/com.yangfuhai.asimplecachedemo/cache/ACache_16609
        ACache manager = mInstanceMap.get ( cacheDir.getAbsoluteFile ( ) + myPid ( ) );
        if (manager == null) {
            manager = new ACache ( cacheDir, max_zise, max_count );
            //Log.v("ACache", cacheDir.getAbsolutePath() + myPid());
            mInstanceMap.put ( cacheDir.getAbsolutePath ( ) + myPid ( ), manager );
        }
        return manager;
    }

    private static String myPid() {
        return "_" + android.os.Process.myPid ( );
    }

    /**
     * Provides a means to save a cached file before the data are available.
     * Since writing about the file is complete, and its close method is called,
     * its contents will be registered in the cache. Example of use:
     * <p>
     * ACache cache = new ACache(this) try { OutputStream stream =
     * cache.put("myFileName") stream.write("some bytes".getBytes()); // now
     * update cache! stream.close(); } catch(FileNotFoundException e){
     * e.printStackTrace() }
     */
    class xFileOutputStream extends FileOutputStream {
        File file;

        public xFileOutputStream(File file) throws FileNotFoundException {
            super ( file );
            this.file = file;
        }

        public void close() throws IOException {
            super.close ( );
            mCacheManager.put ( file );
        }
    }

    // =======================================
    // ============ String数据 读写 ==============
    // =======================================

    /**
     * 保存 String数据 到 缓存中
     *
     * @param key   保存的key
     * @param value 保存的String数据
     */
    //在ACache目录下创建一个文件，文件名为：File(cacheDir, key.hashCode() + “”)。然后将数据存入文件
    public void put(String key, String value) {
        File file = mCacheManager.newFile ( key );
        BufferedWriter out = null;
        try {
            out = new BufferedWriter ( new FileWriter ( file ), 1024 );
            out.write ( value );
        } catch (IOException e) {
            e.printStackTrace ( );
        } finally {
            if (out != null) {
                try {
                    out.flush ( );
                    out.close ( );
                } catch (IOException e) {
                    e.printStackTrace ( );
                }
            }
            mCacheManager.put ( file );
        }
    }

    /**
     * 保存 String数据 到 缓存中一定时间
     *
     * @param key      保存的key
     * @param value    保存的String数据
     * @param saveTime 保存的时间，单位：秒
     */
    public void put(String key, String value, int saveTime) {
        put ( key, Utils.newStringWithDateInfo ( saveTime, value ) );
    }

    /**
     * 读取 String数据
     *
     * @param key
     * @return String 数据
     */
    public String getAsString(String key) {
        File file = mCacheManager.get ( key );
        if (!file.exists ( ))
            return null;
        boolean removeFile = false;
        BufferedReader in = null;
        try {
            in = new BufferedReader ( new FileReader ( file ) );
            String readString = "";
            String currentLine;
            while ((currentLine = in.readLine ( )) != null) {
                readString += currentLine;
            }
            if (!Utils.isDue ( readString )) {
                return Utils.clearDateInfo ( readString );
            } else {
                removeFile = true;
                return null;
            }
        } catch (IOException e) {
            e.printStackTrace ( );
            return null;
        } finally {
            if (in != null) {
                try {
                    in.close ( );
                } catch (IOException e) {
                    e.printStackTrace ( );
                }
            }
            if (removeFile)
                remove ( key );
        }
    }

    // =======================================
    // ============= JSONObject 数据 读写 ==============
    // =======================================

    /**
     * 保存 JSONObject数据 到 缓存中
     *
     * @param key   保存的key
     * @param value 保存的JSON数据
     */
    public void put(String key, JSONObject value) {
        put ( key, value.toString ( ) );
    }

    /**
     * 保存 JSONObject数据 到 缓存中
     *
     * @param key      保存的key
     * @param value    保存的JSONObject数据
     * @param saveTime 保存的时间，单位：秒
     */
    public void put(String key, JSONObject value, int saveTime) {
        put ( key, value.toString ( ), saveTime );
    }

    /**
     * 读取JSONObject数据
     *
     * @param key
     * @return JSONObject数据
     */
    public JSONObject getAsJSONObject(String key) {
        String JSONString = getAsString ( key );
        if (JSONString != null) {
            try {
                JSONObject obj = new JSONObject ( JSONString );
                return obj;
            } catch (Exception e) {
                e.printStackTrace ( );
                return null;
            }
        } else {
            return null;
        }

    }

    // =======================================
    // ============ JSONArray 数据 读写 =============
    // =======================================

    /**
     * 保存 JSONArray数据 到 缓存中
     *
     * @param key   保存的key
     * @param value 保存的JSONArray数据
     */
    public void put(String key, JSONArray value) {
        put ( key, value.toString ( ) );
    }

    /**
     * 保存 JSONArray数据 到 缓存中
     *
     * @param key      保存的key
     * @param value    保存的JSONArray数据
     * @param saveTime 保存的时间，单位：秒
     */
    public void put(String key, JSONArray value, int saveTime) {
        put ( key, value.toString ( ), saveTime );
    }

    /**
     * 读取JSONArray数据
     *
     * @param key
     * @return JSONArray数据
     */
    public JSONArray getAsJSONArray(String key) {
        String JSONString = getAsString ( key );
        try {
            JSONArray obj = new JSONArray ( JSONString );
            return obj;
        } catch (Exception e) {
            e.printStackTrace ( );
            return null;
        }
    }

    // =======================================
    // ============== byte 数据 读写 =============
    // =======================================

    /**
     * 保存 byte数据 到 缓存中
     *
     * @param key   保存的key
     * @param value 保存的数据
     */
    public void put(String key, byte[] value) {
        File file = mCacheManager.newFile ( key );
        FileOutputStream out = null;
        try {
            out = new FileOutputStream ( file );
            out.write ( value );
        } catch (Exception e) {
            e.printStackTrace ( );
        } finally {
            if (out != null) {
                try {
                    out.flush ( );
                    out.close ( );
                } catch (IOException e) {
                    e.printStackTrace ( );
                }
            }
            mCacheManager.put ( file );
        }
    }

    /**
     * Cache for a stream
     *
     * @param key the file name.
     * @return OutputStream stream for writing data.
     * @throws FileNotFoundException if the file can not be created.
     */
    public OutputStream put(String key) throws FileNotFoundException {
        return new xFileOutputStream ( mCacheManager.newFile ( key ) );
    }

    /**
     * @param key the file name.
     * @return (InputStream or null) stream previously saved in cache.
     * @throws FileNotFoundException if the file can not be opened
     */
    public InputStream get(String key) throws FileNotFoundException {
        File file = mCacheManager.get ( key );
        if (!file.exists ( ))
            return null;
        return new FileInputStream ( file );
    }

    /**
     * 保存 byte数据 到 缓存中
     *
     * @param key      保存的key
     * @param value    保存的数据
     * @param saveTime 保存的时间，单位：秒
     */
    public void put(String key, byte[] value, int saveTime) {
        put ( key, Utils.newByteArrayWithDateInfo ( saveTime, value ) );
    }

    /**
     * 获取 byte 数据
     *
     * @param key
     * @return byte 数据
     */
    public byte[] getAsBinary(String key) {
        RandomAccessFile RAFile = null;
        boolean removeFile = false;
        try {
            File file = mCacheManager.get ( key );
            if (!file.exists ( ))
                return null;
            RAFile = new RandomAccessFile ( file, "r" );
            byte[] byteArray = new byte[(int) RAFile.length ( )];
            RAFile.read ( byteArray );
            if (!Utils.isDue ( byteArray )) {
                return Utils.clearDateInfo ( byteArray );
            } else {
                removeFile = true;
                return null;
            }
        } catch (Exception e) {
            e.printStackTrace ( );
            return null;
        } finally {
            if (RAFile != null) {
                try {
                    RAFile.close ( );
                } catch (IOException e) {
                    e.printStackTrace ( );
                }
            }
            if (removeFile)
                remove ( key );
        }
    }

    // =======================================
    // ============= 序列化 数据 读写 ===============
    // =======================================

    /**
     * 保存 Serializable数据 到 缓存中
     *
     * @param key   保存的key
     * @param value 保存的value
     */
    public void put(String key, Serializable value) {
        put ( key, value, -1 );
    }

    /**
     * 保存 Serializable数据到 缓存中
     *
     * @param key      保存的key
     * @param value    保存的value
     * @param saveTime 保存的时间，单位：秒
     */
    public void put(String key, Serializable value, int saveTime) {
        ByteArrayOutputStream baos = null;
        ObjectOutputStream oos = null;
        try {
            baos = new ByteArrayOutputStream ( );
            oos = new ObjectOutputStream ( baos );
            oos.writeObject ( value );
            byte[] data = baos.toByteArray ( );
            if (saveTime != -1) {
                put ( key, data, saveTime );
            } else {
                put ( key, data );
            }
        } catch (Exception e) {
            e.printStackTrace ( );
        } finally {
            try {
                oos.close ( );
            } catch (IOException e) {
            }
        }
    }

    /**
     * 读取 Serializable数据
     *
     * @param key
     * @return Serializable 数据
     */
    public Object getAsObject(String key) {
        byte[] data = getAsBinary ( key );
        if (data != null) {
            ByteArrayInputStream bais = null;
            ObjectInputStream ois = null;
            try {
                bais = new ByteArrayInputStream ( data );
                ois = new ObjectInputStream ( bais );
                Object reObject = ois.readObject ( );
                return reObject;
            } catch (Exception e) {
                e.printStackTrace ( );
                return null;
            } finally {
                try {
                    if (bais != null)
                        bais.close ( );
                } catch (IOException e) {
                    e.printStackTrace ( );
                }
                try {
                    if (ois != null)
                        ois.close ( );
                } catch (IOException e) {
                    e.printStackTrace ( );
                }
            }
        }
        return null;

    }

    // =======================================
    // ============== bitmap 数据 读写 =============
    // =======================================

    /**
     * 保存 bitmap 到 缓存中
     *
     * @param key   保存的key
     * @param value 保存的bitmap数据
     */
    public void put(String key, Bitmap value) {
        put ( key, Utils.Bitmap2Bytes ( value ) );
    }

    /**
     * 保存 bitmap 到 缓存中
     *
     * @param key      保存的key
     * @param value    保存的 bitmap 数据
     * @param saveTime 保存的时间，单位：秒
     */
    public void put(String key, Bitmap value, int saveTime) {
        put ( key, Utils.Bitmap2Bytes ( value ), saveTime );
    }

    /**
     * 读取 bitmap 数据
     *
     * @param key
     * @return bitmap 数据
     */
    public Bitmap getAsBitmap(String key) {
        if (getAsBinary ( key ) == null) {
            return null;
        }
        return Utils.Bytes2Bimap ( getAsBinary ( key ) );
    }

    // =======================================
    // ============= drawable 数据 读写 =============
    // =======================================

    /**
     * 保存 drawable 到 缓存中
     *
     * @param key   保存的key
     * @param value 保存的drawable数据
     */
    public void put(String key, Drawable value) {
        put ( key, Utils.drawable2Bitmap ( value ) );
    }

    /**
     * 保存 drawable 到 缓存中
     *
     * @param key      保存的key
     * @param value    保存的 drawable 数据
     * @param saveTime 保存的时间，单位：秒
     */
    public void put(String key, Drawable value, int saveTime) {
        put ( key, Utils.drawable2Bitmap ( value ), saveTime );
    }

    /**
     * 读取 Drawable 数据
     *
     * @param key
     * @return Drawable 数据
     */
    public Drawable getAsDrawable(String key) {
        if (getAsBinary ( key ) == null) {
            return null;
        }
        return Utils.bitmap2Drawable ( Utils.Bytes2Bimap ( getAsBinary ( key ) ) );
    }

    /**
     * 获取缓存文件
     *
     * @param key
     * @return value 缓存的文件
     */
    public File file(String key) {
        File f = mCacheManager.newFile ( key );
        if (f.exists ( ))
            return f;
        return null;
    }

    /**
     * 移除某个key
     *
     * @param key
     * @return 是否移除成功
     */
    public boolean remove(String key) {
        return mCacheManager.remove ( key );
    }

    /**
     * 清除所有数据
     */
    public void clear() {
        mCacheManager.clear ( );
    }

    /**
     * @author 杨福海（michael） www.yangfuhai.com
     * @version 1.0
     * @title 缓存管理器
     */
    public class ACacheManager {
        private final AtomicLong cacheSize;
        private final AtomicInteger cacheCount;

        private final long sizeLimit;
        private final int countLimit;

        private final Map <File, Long> lastUsageDates = Collections.synchronizedMap ( new HashMap <File, Long> ( ) );
        protected File cacheDir;

        private ACacheManager(File cacheDir, long sizeLimit, int countLimit) {
            this.cacheDir = cacheDir;
            this.sizeLimit = sizeLimit;
            this.countLimit = countLimit;

            cacheSize = new AtomicLong ( );
            cacheCount = new AtomicInteger ( );
            calculateCacheSizeAndCacheCount ( );
        }

        /**
         * 计算 cacheSize和cacheCount
         */
        private void calculateCacheSizeAndCacheCount() {
            new Thread ( new Runnable ( ) {
                @Override
                public void run() {
                    int size = 0;
                    int count = 0;
                    File[] cachedFiles = cacheDir.listFiles ( );
                    if (cachedFiles != null) {
                        for (File cachedFile : cachedFiles) {
                            size += calculateSize ( cachedFile );
                            count += 1;
                            lastUsageDates.put ( cachedFile, cachedFile.lastModified ( ) );
                        }
                        cacheSize.set ( size );
                        cacheCount.set ( count );
                    }
                }
            } ).start ( );
        }

        private void put(File file) {
            int curCacheCount = cacheCount.get ( );
            while (curCacheCount + 1 > countLimit) {
                long freedSize = removeNext ( );
                cacheSize.addAndGet ( -freedSize );

                curCacheCount = cacheCount.addAndGet ( -1 );
            }
            cacheCount.addAndGet ( 1 );

            long valueSize = calculateSize ( file );
            long curCacheSize = cacheSize.get ( );
            while (curCacheSize + valueSize > sizeLimit) {
                long freedSize = removeNext ( );
                curCacheSize = cacheSize.addAndGet ( -freedSize );
            }
            cacheSize.addAndGet ( valueSize );

            Long currentTime = System.currentTimeMillis ( );
            file.setLastModified ( currentTime );
            lastUsageDates.put ( file, currentTime );
        }

        private File get(String key) {
            File file = newFile ( key );
            Long currentTime = System.currentTimeMillis ( );
            file.setLastModified ( currentTime );
            lastUsageDates.put ( file, currentTime );

            return file;
        }

        private File newFile(String key) {
            return new File ( cacheDir, key.hashCode ( ) + "" );
        }

        private boolean remove(String key) {
            File image = get ( key );
            return image.delete ( );
        }

        private void clear() {
            lastUsageDates.clear ( );
            cacheSize.set ( 0 );
            File[] files = cacheDir.listFiles ( );
            if (files != null) {
                for (File f : files) {
                    f.delete ( );
                }
            }
        }

        /**
         * 移除旧的文件
         *
         * @return
         */
        private long removeNext() {
            if (lastUsageDates.isEmpty ( )) {
                return 0;
            }

            Long oldestUsage = null;
            File mostLongUsedFile = null;
            Set <Map.Entry <File, Long>> entries = lastUsageDates.entrySet ( );
            synchronized (lastUsageDates) {
                for (Map.Entry <File, Long> entry : entries) {
                    if (mostLongUsedFile == null) {
                        mostLongUsedFile = entry.getKey ( );
                        oldestUsage = entry.getValue ( );
                    } else {
                        Long lastValueUsage = entry.getValue ( );
                        if (lastValueUsage < oldestUsage) {
                            oldestUsage = lastValueUsage;
                            mostLongUsedFile = entry.getKey ( );
                        }
                    }
                }
            }

            long fileSize = calculateSize ( mostLongUsedFile );
            if (mostLongUsedFile.delete ( )) {
                lastUsageDates.remove ( mostLongUsedFile );
            }
            return fileSize;
        }

        private long calculateSize(File file) {
            return file.length ( );
        }
    }

    /**
     * @author 杨福海（michael） www.yangfuhai.com
     * @version 1.0
     * @title 时间计算工具类
     */
    private static class Utils {

        /**
         * 判断缓存的String数据是否到期
         *
         * @param str
         * @return true：到期了 false：还没有到期
         */
        private static boolean isDue(String str) {
            return isDue ( str.getBytes ( ) );
        }

        /**
         * 判断缓存的byte数据是否到期
         *
         * @param data
         * @return true：到期了 false：还没有到期
         */
        private static boolean isDue(byte[] data) {
            String[] strs = getDateInfoFromDate ( data );
            if (strs != null && strs.length == 2) {
                String saveTimeStr = strs[0];
                while (saveTimeStr.startsWith ( "0" )) {
                    saveTimeStr = saveTimeStr.substring ( 1, saveTimeStr.length ( ) );
                }
                long saveTime = Long.valueOf ( saveTimeStr );
                long deleteAfter = Long.valueOf ( strs[1] );
                if (System.currentTimeMillis ( ) > saveTime + deleteAfter * 1000) {
                    return true;
                }
            }
            return false;
        }

        private static String newStringWithDateInfo(int second, String strInfo) {
            return createDateInfo ( second ) + strInfo;
        }

        private static byte[] newByteArrayWithDateInfo(int second, byte[] data2) {
            byte[] data1 = createDateInfo ( second ).getBytes ( );
            byte[] retdata = new byte[data1.length + data2.length];
            System.arraycopy ( data1, 0, retdata, 0, data1.length );
            System.arraycopy ( data2, 0, retdata, data1.length, data2.length );
            return retdata;
        }

        private static String clearDateInfo(String strInfo) {
            if (strInfo != null && hasDateInfo ( strInfo.getBytes ( ) )) {
                strInfo = strInfo.substring ( strInfo.indexOf ( mSeparator ) + 1, strInfo.length ( ) );
            }
            return strInfo;
        }

        private static byte[] clearDateInfo(byte[] data) {
            if (hasDateInfo ( data )) {
                return copyOfRange ( data, indexOf ( data, mSeparator ) + 1, data.length );
            }
            return data;
        }

        private static boolean hasDateInfo(byte[] data) {
            return data != null && data.length > 15 && data[13] == '-' && indexOf ( data, mSeparator ) > 14;
        }

        private static String[] getDateInfoFromDate(byte[] data) {
            if (hasDateInfo ( data )) {
                String saveDate = new String ( copyOfRange ( data, 0, 13 ) );
                String deleteAfter = new String ( copyOfRange ( data, 14, indexOf ( data, mSeparator ) ) );
                return new String[]{saveDate, deleteAfter};
            }
            return null;
        }

        private static int indexOf(byte[] data, char c) {
            for (int i = 0; i < data.length; i++) {
                if (data[i] == c) {
                    return i;
                }
            }
            return -1;
        }

        private static byte[] copyOfRange(byte[] original, int from, int to) {
            int newLength = to - from;
            if (newLength < 0)
                throw new IllegalArgumentException ( from + " > " + to );
            byte[] copy = new byte[newLength];
            System.arraycopy ( original, from, copy, 0, Math.min ( original.length - from, newLength ) );
            return copy;
        }

        private static final char mSeparator = ' ';

        private static String createDateInfo(int second) {
            String currentTime = System.currentTimeMillis ( ) + "";
            while (currentTime.length ( ) < 13) {
                currentTime = "0" + currentTime;
            }
            return currentTime + "-" + second + mSeparator;
        }

        /*
         * Bitmap → byte[]
         */
        private static byte[] Bitmap2Bytes(Bitmap bm) {
            if (bm == null) {
                return null;
            }
            ByteArrayOutputStream baos = new ByteArrayOutputStream ( );
            bm.compress ( Bitmap.CompressFormat.PNG, 100, baos );
            return baos.toByteArray ( );
        }

        /*
         * byte[] → Bitmap
         */
        private static Bitmap Bytes2Bimap(byte[] b) {
            if (b.length == 0) {
                return null;
            }
            return BitmapFactory.decodeByteArray ( b, 0, b.length );
        }

        /*
         * Drawable → Bitmap
         */
        private static Bitmap drawable2Bitmap(Drawable drawable) {
            if (drawable == null) {
                return null;
            }
            // 取 drawable 的长宽
            int w = drawable.getIntrinsicWidth ( );
            int h = drawable.getIntrinsicHeight ( );
            // 取 drawable 的颜色格式
            Bitmap.Config config = drawable.getOpacity ( ) != PixelFormat.OPAQUE ? Bitmap.Config.ARGB_8888 : Bitmap.Config.RGB_565;
            // 建立对应 bitmap
            Bitmap bitmap = Bitmap.createBitmap ( w, h, config );
            // 建立对应 bitmap 的画布
            Canvas canvas = new Canvas ( bitmap );
            drawable.setBounds ( 0, 0, w, h );
            // 把 drawable 内容画到画布中
            drawable.draw ( canvas );
            return bitmap;
        }

        /*
         * Bitmap → Drawable
         */
        @SuppressWarnings("deprecation")
        private static Drawable bitmap2Drawable(Bitmap bm) {
            if (bm == null) {
                return null;
            }
            BitmapDrawable bd = new BitmapDrawable ( bm );
            bd.setTargetDensity ( bm.getDensity ( ) );
            return new BitmapDrawable ( bm );
        }
    }

}

